Add butter to a medium skillet over medium heat, let melt and brown slightly. Add onion and cashews, stir occasionally until onions are soft and lightly browned, 4-5 minutes. Add garlic and ginger and stir occasionally until soft, 1-2 minutes. Add tomato paste, water, honey, paprika, coriander, Garam Masala and bay leaf. Turn heat to medium low and let simmer 10 minutes. Remove bay leaf and transfer sauce mixture to a blender. Blend until smooth. Add salt to taste to sauce. Set aside to cool. Preheat oven broiler to low. Spread slices of Pane Turano with thin layer of masala sauce and top with slices of paneer. Brush paneer lightly with oil. Place under broiler for 2-3 minutes or until paneer is lightly browned. Top with more masala sauce (if desired), sprinkle with cilantro and serve.